Induction Methods – Artificial Rupture of Membranes (AROM)

Amniotomy also known as “artificial rupture of membranes” is where the membranes are ruptured / released by the midwife using a gloved finger that has a hook on the end (amnicot) or a little device called an amnihook.

This allows the amniotic fluid to be released.

The World Health Organisation (WHO) recommends that in normal labour there should be a valid reason to interfere with the spontaneous timing of the rupture of the membranes. Amniotomy should be reserved for women with abnormal labour progress.

One of the reasons for rupturing your membranes is if your baby needs to be monitored by a foetal scalp clip you would need your membranes to be released.

Rupturing the membranes may trigger the release of prostaglandins, which may then start your contractions as well.

Once the hook reaches the amniotic sac, the tip is pushed up against the sac with the index or middle finger of the internal hand to pierce the membranes. The hook is then pulled through the membranes with the external hand holding the handle to create a hole in the sac.

If an amniotic finger cot is being used, the pointed tip is dragged through the membranes with the finger to create the amniotomy.

AROM Benefits

• May shorten the length of labour;
• Reduces the need to use pharmaceutical drug induction;
• Allows health care providers to check the liquor;
• May help the position and descent of baby.

 

AROM Risks

• Umbilical cord prolapse where the fluid has caused the umbilical cord to come out before the head and may inhibit oxygen going through to baby, which will result in emergency caesarean;
• Cord compression associated with variable decelerations of the fetal heart rate occurs more often after AROM;
• Rupture of a vasa praevia, resulting in emergency caesarean;
• Risk of further interventions if labour doesn’t start;
• Risk of infection after a prolonged time between rupture and birth;
• Increases the risk of caesarean section

 

Here are the RANZCOG Guidelines for induction of labour in Australian and New Zealand:

Induction-labour-pamphlet

 

OTHER INDUCTION METHODS

Stretch & Sweep – CLICK HERE

Balloon Catheter (Foley’s or Cook’s) – CLICK HERE

Prostaglandin Gels – CLICK HERE

Synthetic Oxytocin (Syntocinon) – CLICK HERE